title: A human proteome microarray identifies that the heterogeneous nuclear ribonucleoprotein K (hnRNP K) recognizes the 5' terminal sequence of the hepatitis C virus RNA.
abstract: Stem-loop I (SL1) located in the 5' untranslated region of the hepatitis C virus (HCV) genome initiates binding to miR-122, a microRNA required for hepatitis HCV replication. However, proteins that bind SL1 remain elusive. In this study, we employed a human proteome microarray, comprised of ∼17,000 individually purified human proteins in full-length, and identified 313 proteins that recognize HCV SL1. Eighty-three of the identified proteins were annotated as liver-expressing proteins, and twelve of which were known to be associated with hepatitis virus. siRNA-induced silencing of eight out of 12 candidate genes led to at least 25% decrease in HCV replication efficiency. In particular, knockdown of heterogeneous nuclear ribonucleoprotein K (hnRNP K) reduced HCV replication in a concentration-dependent manner. Ultra-violet-crosslinking assay also showed that hnRNP K, which functions in pre-mRNA processing and transport, showed the strongest binding to the HCV SL1. We observed that hnRNP K, a nuclear protein, is relocated in the cytoplasm in HCV-expressing cells. Immunoprecipitation of the hnRNP K from Huh7.5 cells stably expressing HCV replicon resulted in the co-immunoprecipitation of SL1. This work identifies a cellular protein that could have an important role in the regulation of HCV RNA gene expression and metabolism.
authors.affiliation: Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405;
authors.forename: Baochang
authors.initials: B
authors.lastname: Fan
authors.forename: Kuan-Yi
authors.initials: KY
authors.lastname: Lu
authors.forename: F X
authors.initials: FX
authors.lastname: Reymond Sutandy
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Chen
authors.forename: Kouacou
authors.initials: K
authors.lastname: Konan
authors.forename: Heng
authors.initials: H
authors.lastname: Zhu
authors.forename: C Cheng
authors.initials: CC
authors.lastname: Kao
authors.forename: Chien-Sheng
authors.initials: CS
authors.lastname: Chen
mesh_terms: D015967:Gene Expression Regulation, Viral; D016174:Hepacivirus / Q000235:genetics* / Q000472:pathogenicity; D006505:Hepatitis / Q000235:genetics / Q000821:virology*; D034641:Heterogeneous-Nuclear Ribonucleoprotein K / Q000235:genetics*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D040081:Protein Array Analysis; D020543:Proteome; D012367:RNA, Viral / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
chemical_list: D034641:Heterogeneous-Nuclear Ribonucleoprotein K; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D020543:Proteome; D012367:RNA, Viral; D016601:RNA-Binding Proteins